The overall objective of the project is to learn more about the structure and function of eukaryotic chromosomes, particularly at the molecular level. We are characterizing the free and integrated copies of the rDNA genes in Tetrahymena with emphasis on the mechanism of gene amplification. We have also begun an analysis of the histone genes in the same protozoan. Another project involves characterization of the RNA synthesized during the lampbrush chromosome stage of amphibian oogenesis. This is being done by in situ hybridization of various DNA probes to the RNA of the chromosomes in cytological preparations.